The Daily Mile and children’s physical activity, mental health and educational performance: a quasi-experimental study in Greater London primary schools

Objectives: To examine associations between The Daily Mile, a school-based active mile intervention, and pupils' physical activity, mental health and educational performance. Methods: Year 1 pupils (aged 5-6 years) from Greater London primary schools were invited. Schools were allocated to The Daily Mile or non-Daily Mile group based on their reported Daily Mile participation. We measured weekday school hours mean minutes of moderate-to-vigorous physical activity (MVPA) using GENEActiv accelerometers. Other outcomes included time spent sedentary and in light activity, mental health and educational performance. Multi-level linear regression models examined differences accounting for repeated measurements (day) clustered by pupils-, class- and school-level, with adjustments for sex, ethnic group, area-level deprivation and month of assessment. Results: A total of 1004 pupils/40 schools were recruited and assessed between October 2021 and January 2023; 21 schools/499 pupils comprised The Daily Mile group; 19 schools/505 pupils the non-Daily Mile group. Daily Mile pupils spent 2.2 min more in MVPA compared with non-Daily Mile pupils, but the difference was not significant (0.78, 95% CI -2.14 to 3.69). Daily Mile pupils spent less time sedentary and more time in light activity compared with the non-Daily Mile pupils, but not significantly (-5.06, 95% CI -15.37 to 5.26 and 3.27, 95% CI -4.26 to 10.81, respectively). There were no differences in mental health or educational performance. Conclusions: We found no associations between The Daily Mile and pupils' physical activity, mental health and educational performance. Pupils in our study were in year 1 with early exposure to the intervention; assessments over longer periods are needed to understand any benefits.